"I’ve known Heather for many years. She was an effective spokeswoman for the Department of State and enjoys the confidence of Secretary Pompeo and President Trump," Graham wrote.

"I’m sure she will perform well at her hearing and look forward to supporting her nomination," he added.

Trump announced Nauert's nomination in a tweet Friday, one day after reports surfaced of her selection. Nauert was reported to be a top choice on Trump's shortlist for the position.

Nauert, a former Fox News anchor, joined the Trump administration last year as a spokeswoman for the State Department. She now faces a confirmation battle in the GOP-controlled Senate, which confirmed Haley easily to the position last year.

Haley, her predecessor, announced was was resigning from the Trump administration unexpectedly in October, downplaying rumors of future political ambitions.

"No, I am not running in 2020," Haley told reporters at the time. “I look forward to supporting the president in the next election."